Connector circuit employing a sequence switch



July

Filed C. E. LOMAX CONNECTOR CIRCUIT EMPLOYING A SEQUENCE SWITCH 2SHEETSSHEET 1 May 16, 1950 GEN. I

FIG. I

INVENTOR. CLARENCE E. LOMAX ATTORNEY July 1, 1952 c. E. LOMAX CONNECTORcmcun' EMPLOYING A SEQUENCESWITCH 2 SHEETSSHEET 2 Filed May 16, 1950 mQC 102 N vm wk mO N wzOELwOa wmzj m0 QDOKO cum-02D: nzN OP INVENTOR.CLARENCE E. LOMAX ATTORNY Patented July 1, 19 52 SEQUENCE SWITCH tomaticElectric Laboratories, Inc.,

" "Clarence E. Loniamflhicago; 111., assignor to Au- Chicago,

' "This invention relates in general to telephone systems and moreparticularly-to telephone systems which utilize sequence switches inplace of relays to perform the necessary circuitoperations. The use 'oi'a sequence/switch per se is not newin the telephone art'rbut thisinvention was conceived to advance theart in the use or the sequenceswitch in telephone circuits. One circuit'in which the sequence-.'switch may be used to great-advantage is the party line connectorshown in detail in thegdisclosure oi the inventive ideafi" One' objectof this invention is to provide a telephone]; switch circuit whichoperates in response to aplurality 'oi series" of impulses inwhich-there is a sequence switch-movable into a plurality of positionsand designed to perform various circuit functions in response to themovement into the various "positions, the telephone'switch circuitbeing'designed "so that the sequence switch willmove into one certainposition'i-n response to one-of said series of impulses'rega-rdless ofthe numberyof impulses (in the series and will move into a differentoneo'f said positions .in response to each impulse in the succeedingseries of impulses. 7

Another object *of the invention is to provide a connector circuit whichoperates in response to the receipt of a "plurality'of series ofimpulses to vconnect with called iines accessible from the connectorcircuit in which *there is a stepping sequence switch designed-toperform various circuit functions in response to the movement into thevarious positions, the "connector circuit be ing designed so-that the.sequence switch will take one step in response to me receipt of thefirst of said series of impulses regardless of the number'- of mpulsesin the series; asecond step teams. (01. 119-41) ing signal to be appliedto the line and the side of the line to which the signal is to beapplied. Still another object of this invention is to provide in a twohundred point connector .of the type described in the immediatelypreceding object'that the sequence switch will also select the. hundredsgroup-in which the called party line is located.

, Still another object of this invention is to provide a sparksuppressor which is connected in the pulsing circuit soasto be common tothe tens and units selecting device and also to the sequence switch. v

Another object of this invention is to provide a party line connectorcircuit which operates in response to a plurality ofseries of impulsesto connect'with a called party line in which there is a sequenceswitch'which operates once in .response to a. first seriesof impulsesregardless of the number of impulses in the series to trans- ,ferthe puling circuit of the connector from the tens selecting device to the'unitsf selecting device, then operates once in response to the secondseries of impulses regardless of the numin response to the receipt pfthefsecond of said series-oi impulses regardless of the number ofimpulses in the series, and a stepin response to each impulse receivedin fthe remaining series of impulses. 7 c I V Another object of thisinventionis to provide a party line connector circuit which operates inresponse to .a p'lurality' '91 series of impulses to connect with acalledparty'li'ne accessible to the connector circuit and 1:0 signal oneof the subscribers on the par ty line-in which there is asequen'ceswitch designed to perform various .circuit functions, the circuit beingso constructed that the sequence switch will operate .to transfer thepulsingcircuitjin the connector Irom the e s filec ion device to the'-"units selection device and will also operate to select the ringher ofimpulses in the series-to transfer the pulsing-circuit of the connectorfrom the units'' selecting device tothe sequence switch drivingmechanism, and then operates once in response to each of the impulsesin-the remaining series of impulses to select; the ringing signal to beapplied to the line, and also to select the side of the line to whichthe signal is to be applied, anda-lso to select the hundreds group; inwhich the call.- ing line is connected lithe party line connector is atwo hundred line connector.

The invention will "appear more clearly, and further objects will becomeapparent, from the following detaileddescription when taken :inconnection with the accompanying drawings, showing by way of example, apreferred embodiment of the inventive idea.

Figs. 1, 1A, 2 and ,3, inclusive, depict a telephone system which bestillustrates the present invention. 'More specifically, Figs; .1 and 1Ashow -a' connector circuit and associated switch train :for enablin asubscribersuchas at substation A tolcomplete a .connection'to a party.line such as lines 1101 or 104. theiconnector circuit including springpile-ups Pl .110 ,P}i2, inclusive, of the sequence switch shown..inl1iig..2. The v..se, quence switch of Fig. .2 includes an operating magnet1'94, pawl I96, ratchet. 195,. and [a plurality. of cams and springpile-ups. [Fig shows the cams in a graphical form." I v i Referringfirst to Fig.2, the sequence switch shown therein is 01 the step-by-steppawl driven type, the cams I to 6, inclusive, which comprise the switchbeing fixedly secured on a common shaft to which there is also fixedlyattached a ratchet I95 designed to cause the shaft and thus the cams totake thirteen steps to complete one revolution. 1 The-,ratchet I95 isdriven by a pawl I96 controlled by; an 'electro-rnagnetic I94, theswitch being of the reverse drive type, i. e. the switch will triggeritself on the operation of the magnet and will step on the release ofthe magnet. There are six cams-*in-the sequence switch shown, the camsbeing labeled I to 6,- in

elusive, and associated with each camis gon -or more spring pile-ups,each pile-upv consisting Qof i one or more sets of spring contacts. Thespring pile-ups PI to PI2, inclusive, are associated with I30 operates,grounds the C lead at contacts I34 tc mark this circuit busy in theselector banks and to hold the preceding switch train under control;;'ofthis connector circuit, and prepares their respective cams inpredetermined space rela-'- tionships, the reason for which will becomeapparent. The sequence switch has a normal po- Sition which it assumeswhen the connector circui't is not in use, the 'switch'in Fig. 2 beingshown in its normal position. Besides the normal position, the switchhas. twelve other positions or steps. thusrnaking a total of 'thirteen.Certain ones'of the springpile ups are operatedin each position of "thesequence switch and certain of the pile-ups are operated more than oncein each revolution of the cam For instance, the pileups PI and P21areopera'te'd an'd'their contact sets open'whenthesequence switch is inthe normal position; pile-up P3 will be operated by cam 2'on 'the'firstste'p'of the sequence switch, at which time pile-.up P2 will berestored; pile-up PI willbejcp'erated and restored five times in onerevolution, at" the 4th,:"6th, 8th, 10th and 12th positions-or steps. Itwould be'just as feasible to provide a greater 'numberof. cams sothatthe spring pile-up could be inalignment when the sequence switch isconstructed, but six cams will adequatelyTsery/e for the purpose ofillustration. The Qfline connector showninFigs. land 1A is arranged tooperate with five-party party linesfhaving either harmonic ringing orcode ringing, ','the ringers being either; divided or relay I20 -to ,1the, vertical magnet the pulsing circuit from the back contacts I22 01'I90 and relay I 25.1" hils cireuit is now prepared to receive a firstseriesof impulses transmitted from the subscribers dial. Relay I20follows the first series ofimpulse's, closing and opening, at contactsI22,

Y the pulsing circuit to the vertical magnet I90 and bridged onthepartylines in a well-known man- More particularly: if the. third digitis composed offrom one to five impulses, inclusive, the connectorcircuit will test and seize, if idle, a party line in the 'firsthundredgroup of, party lines while if the digit is composed of-from six to tenimpulses, inclusive, a party line in thesec- 0nd hundred group oflines'will be tested and seized if idle. With eachdiiferent impulse ofthe firstfive' impulses in the third digit, adifierent frequency or codeis selected and a particular one side of the line to which the ringingsignal is to be connectedoveris also selected. On all odd digits in thethird series of impulses, the ringing signal, will be connected over thenegative side of the line while on even" digits the signal will beconnected over the positive side.

This party line connector is accessible to subscriber A over the linecircuit, finderand selector in a well known manner. This connector ismarked idle on thebanks of the battery-searchto slow operating relay;I25 by way of contacts I33, contacts 4, of spring pile-ups P6 and P5,and contac'ts" 13's. an spr ng 'f'piIe-up' P2. "Relay" I30isfslowto-release and will remain operated during 'iinpulsing; IRelayI25jop'era'tes on the first impulse by. way of contacts I22, I33, 4 ofspring pile-ups'PIi and P5,. and"l36f and remains operated 'for. therem'ainir'ig', impulses of the first digit due to. its slow-releascharacteristics I Relay vI215 on'operating closes the circuit to relayI40"at contacts .',I2j I5 Relay I40 operates and closes the circuit tosequence switch magnet I 94 at contacts'l46 by way of contact 2 ofspring pile up P4. ,The vertical magnet I responds to the first digit tostepfthe istrowger switch wipers to. the bank level correspondingto-thefirst digit. Qnth'e first vertical stepof-the switch wipers, the 'VIO.N.springs operate Qto. prepare a release circuit to be subsequentlydescribed.

The sequence switch magnet -I 94.- operates and remains operated duringthe first series of impulsesa'sdoes relay I40.. fIhesequence switchis ofthe reverse drive type, 1., e it takes one step eachtime' the sequenceswitch magnet releases after operation, and therefor th sequence switchdoes not'step at thistime- At the termination .otf the st series ofimpulses, relay I 20- remains steadilyoperated, the circuit ,toslow-release relay I25 being open at contacts I22. niter'a shortdelay,relay I25 releases, vopenin the circuit to relay I40 at contact I26..,}R e1ay. I40; release o nin the circuit to the sequence switch magnet I94 at "contacts I46. Magnet .I'94 releases and. g the sequence switchsteps fro m the normal position to the first position 'causing'fspringpile-ups PI -rand P2-to release and ,spring. pile-up P3, to operate,Release of pile-.upfPI prepares. =seyera-l. circuits to besubsequently,@explainedfand release of pile-up P2openslthepulsing'circu't t I 90., Operation-of pile-up P3 closes; thepulsing circuitfito thefrotaryjinagnet I-93 The connector isnowprepared'toreceive: a'second series of impulses 'correspondingto a digittransmitted from the dialof subscriber .1Relayjl20 f ollows'the second.seriesl'of impulses received ever the use 1016 and this circuit operatesin the same manner asrld'escribedfor the first digit with the exceptionthat the rotary magnet I 93 is operatedjrather than the vertical magnet1190. Relays "I25 and I40 are operated as is the sequence switchmagnetI94. The rotary magnet steps the Strowg'e'r switch wipers to the bankcontacts terminatingjthe partylines designatediiby this second digitdialed intothe connectozg Atthis time;.each set of wipers is standtion}to position 2.

ing on a set'of bank contacts which terminate a partyline, the-lowersetbeing connected with a line in the first hundreds group of -party lines(either line -IOI or line.;I-04)-,.;and the upper set being connectedwith a line in the "second hundreds group of party lines. Before thethird digit is dialed, there is no way of telling which of the two partylines is desiredand theline wipers are open at pile-ups P and. P6.Thecontrol wipers C are also open at P5, and P5 sothat any potentialpresent on the C terminals passed over by the wipers during the rotarymovement would have no eifect on the connector.

After the termination of the second series of impulses, relayv I remainssteadily operated, holding the circuit to slow-release relay I open atcontacts I22. "Relay I25 releases and opens relay I49. Relay. I40releases, opening the circuit tozthe sequence switch magnet I94. MagnetI94 releases, stepping the sequence switch fromv posi- In position 2,spring pile-up P3 restores and pileeup P4 operates: of pileup;P9 opensthe pulsing circuit to the rotary magnet I93. Operation of springpile-up P4 transfers the: control of the sequence switch magnetlet fromrelay I40 by way of contacts I45 and ,2 of pile-up P4 to the pulsingcircuit by way of contacts I of pile-up P4. The circuit is :now' readyto receive'the third and last digit, the digit which selects the properhundreds group, the ringing code orfrequency to be applied over theparty line, and the side of the line to which theringing will beapplied. It should be notedthat the well-known type spark suppressormade. up of condenser C- and resistor R. is connected in the pulsingcircuit. so as to be used in common by the pulsing circuit intransmitting pulses to the vertical,rotary, and sequence switch magnets.I ,A brief-summary of how the circuit functions in response to the thirddigit will now be given followed by a detailed description of calls to aparty. line in each of the hundreds group.

As noted, the sequence switch magnet I94 is now connected in the pulsingcircuit and the sequence switch magnet will follow the third digit,causing the sequence switch to step once for each impulse received. Thesequence switch is thus converted into a selecting switch. In response.to thefirst impulse of the third digit, the sequence switch will stepfrom position 2 to position 3, in response to the fifth impulse it willstep from position 6 to position I, etc. Spring pile-up P5 operates inresponse-to the first impulse and remains operated thru the fifthimpulse, connecting the party line inthe first hundreds group of .calledlines thru tothe connector. Spring pile-up P5'releases and pile-up P6operates in response to the ixth impulse, pile-up P6 remaining operatedfor the sixth to tenth impulses. Pile-up P6 connects the party line inthe second hundreds group of party lines thru tothe connector. Springpile-ups P8 to 'PI2 operate and release successively in positions 3' toI, respectively, in responseto'the first five impulses of thethirdidigit and again inpositions 0 to H,

respectivelysin response tothe last five impulses ofthethird'digit..--..These spring pile-ups serve to connect the properringing frequency or ringing code tojthegcalled partyline. Also on eacheven; impulse ofv the third digit, spring pile-tip P! is operated whileon each odd impulse P1 is released. The operation and release of-pile-up PI transfers the ringing circuit from one, sideof the partyline to the other side to-providefor-divided Restoration ringingwheresuch a ringing systemis employed; It should :be noted that theconnector may be arranged forcharmonic ringing or codeiringing. The codeorlharmonic frequencies are connected to the. circuit byway of Gen. toGen. 5' leads. Aringback signal is returned by way of Gen. 2 inv onecase or by. :way of. relay I60 and all the Gen. leadsin another case;'The ringback circuit thrurelay M50 is preferably used when code ringingis used so thatthecalling party will hear the codesignal thatisbeingssent over the called party line. p

As :an example, letus .assume that the third digit dialedby the callingparty is a 3. Relay.

I20 .follows the dial impulses received over the callingxline loop andin tur-ncausesthe pulses tobe repeated :to relay I25 and the sequenceswitch magnet I94 by way :of contacts I22. Relay I25 operates on thefirst impulse of the third digitiand remains steadily operated duringimpulsing due to its slow-release characteristics, the'.impulsingcircuit being traceable from contactsa l22, through contacts I33,contacts 4 of pile-up P5 andP5, and contacts-I35. The sequence'switchmagnet I94 operates, by way of contacts I22, =I33, '4 of pile-ups P6 andP5, and contactsl of pile-up P4, once for each impulse received, causingthe sequence switch to take one step each time the magnet I94 releases.Relay I25, on operating for the first impulse, closes relay I40 whichoperates to connect relay I50 to eachof the vC wipers :by way ofcontacts MI and pile-ups P5and P5. Relay I40 also closes amultiplepu-lsing circuit to'relay I25 and the magnet I94 at contactsI45-to insure the continued pulsing of magnet I94when the originaloperating circuitis openedat contacts 4 of pile-up P5.

- In response to the first impulse of the third digit, the sequenceswitch steps from position 2 to position 3, pile-41p P4 remainingoperated-and pile-up P5 and P0 operating inposition 4, Pileup. P4remains operated until the sequence switch return' to the normalposition. I Operation of P5 closes the and line leads to the party lineIOI or 404 thru contacts I and 2, respectively, closes the C lead to theparty line thru contact 3, and opens the original pulsing circuit to thesequence switch I94 at contacts 4. If'the party line in the firsthundreds group is idle, battery thru the CO relay (notshown) in theline-circuit I00 or I03 on the 0 lead willprevent relay I50 fromoperating in a'well-known'manner and this circuit will remain as isuntil the end of the third digit. But 'if the party line is busy, groundwill be standing on the C lead in the line circuit and relay I50willoperate immediately after pile-up P5 operates by way of contacts MI andcontacts '4 of pile-up P5. This operation of relay I50 occurs even ifthe party line in the second hundreds group is the one desired but theoperation does not affect the circuit until after the termination ofpulsing since the holding circuit .of relay I50 is opened during pulsingby relay I40 at contacts I42andsince the dialmechanism at the callingstation holds the receiver circuit open during dialing thus preventingthe calling party from hearing the busy tone connected to the line atcontacts I5I. Pile-up P5 remains operated for the three pulses of thethird digit. In response to the first impulse, with the sequence switchin position 3, pile-up P8 operates to close one of the generatorcircuitsor code ringing circuits to the ringing circuit thru relay I60, theringing circuit at this time being open -:at contacts I51. In responseto the second'impulse, pile-up P8 releases 7 andplle-up P9 operates toclose the second ringing signal thrurelay .I60. vIn response to thethird impulse, which under the assumption is the last, pile-up P9releases and pile-up PIO operates, closing the harmonic ringingfrequency or code ring connected to the Gen. 3 lead to relay I60. Springpile-up P1-,'which" had operated on the second impulse,'is.released onthe third impulse to prepare the incomplete .circuit from the Gen. 3 tothe side of the party line. by way of contacts 4 of P1. Atthetermination of the third impulse, relay I20 remains steadily operated,opening the circuit at contacts I22 to relay I25. Relay I25 releases,opening relay I40. Relay I40 releases. Assume, that the called partyline in the first hundreds group is busy. Relay I50 would have operatedfrom ground on the C lead in the line circuit as previously explained.Release of relay I40 closes a holding circuit to relay I 50 from'the Clead by way of contacts I42 and I52 and then opens the originaloperating circuit to relay I50. This holding circuit is to insure thatthe busy condition of theconnector will remain even if the partylinesubsequently'becomes idle. Relay I50 closes busy tone by way of contactsII to the calling party over the line. The connector remains in thisposition until the calling party releases the connection.

When the calling party releases after receiving the busy signal, theline loop is opened and relay I20 releases, opening relay I30. Relay I30releases, removing ground from the C lead at contacts J34 to release thepreceding switch train, closing an alarm circuit by way of contacts I88,I35, and contacts 2 of PI to cause a delayed alarm in case the sequenceswitch should fail to return to normal, opening the holding circuit torelay I50 at contacts I3I, and closing the circuit to the Strowgerswitch release magnet I21 by way of contacts I22, I32,-I34 and I92 ofthe V. O. N. springs. Although ground isremoved from the C terminal inthe selector banks, this connector remains busy to searching selectorsbecause the,

circuit to the'resistance battery is; held open at contactsnl ofPI.Relay I50 releases. The release magneti operatesqto return'the Strowgerswitch to normal. In the normal position, the V. O. N. springs restore,openingv contacts I92 and closing contacts l9I. A homing circuit isclosed to the sequence switch magnet I94 by way of contacts I22, I32,I84, I9I, 3 of pile-up PI, and I91 of magnet I94, The sequence switchautomatically operates in thisself-interrupting circuit to step to thenormal position. In the ,normal position, pile-up PI operates to openthe selfinterrupting circuit to stop the stepping, opens the alarmcircuit at contacts 2, and closes the resistance battery to the Cterminal in the selector banks by way of contacts I of PI tomark thiscircuit as idle to searching selectors. The connector is now at normal.

If the called line in the first hundredgroups is idle, relay I50 is notoperated and when relay I40 releases after impulsing it closes 'acircuit at contacts I43 from ground thru contacts I3I, I53,lowerjjwinding relay I80 and contacts 3 to,P5 to the battery connected0.10. relay (not shown) on theC lead in the line circuit. Relay I80operates, closes..its X contacts I83 first to lock itself up thru itsupper winding to ground at contacts I3I and then grounds the 0 lead tothe line circuitto hold the cutofl relay operated and to. mark'the linecircuit as busy to other connectors, closes the pick up lead P. U.;torelay.-I5.5xbyiway of contacts I86,

and closes a part of the talking circuit at contacts' I8I and I82.At'the beginning of the next cycle 'ofthe' ringing machine in theexchange, the P. U. lead is momentarily grounded to operate relay 'I55.Relay I55 locks itself up by way of contacts l59, I11 and I81. Relay I55closes the ringing signal on the Gen. 3 lead thru slow-operate relay I60to the side of the line --by way of contacts I51,'4'o1 P1, IN and .I8I,and also closes a ringback signal to the calling party 'by way ofcontacts I56. If code signals and bridged ringing is used, all theringers on the line will ring the code. If code signals and dividedringing is used, all the ringers on the side of the line will ring thecode. If frequency ringing is used, only the proper harmonic ringer willring. Such systems of ringing are well known in the telephone art.

When the call .is answered by a party on the party line, the line loopis closed thru the answering telephone circuit and relay I60 operatesfrom the battery connected to the generator by way .of P10, contactsI51, 4 of P1, I1I, I8I, I of P5, the line loop, contacts 2 of P5, I82,I13, and 3 of P1 to ground. Relay I60 operates and closes relay I10 at.contacts IBI. Relay I10 operates, closes its holding circuit thru thelower winding of relay I by way of contacts I16, I43, I53 and I3I, opensrelay I55, opens the P. U. lead, switches the line leads thru to thecalled line at contacts I12 and I14, and prepares the SUPY. lead atcontacts I15. Relay II 0 operates over the called line loop in awell-known manner and reverses the battery thru relay I20 on the callingline leads to give a supervisory signal for metering, etc. Relay IIOalso connects' ground to the windings of relay I80 at contacts II5 tohold this circuit under control of the called party. Relay I55 releasesto open the ringing circuit at contacts I51 and also to openthe-ringback signal at contacts I56. If the calling party releasesfirst, relay I20 releases and in turn releases relay I30. Release ofrelay I30 closes ground to the SUPY. lead byway of contacts I22,-I32, Iand I15 to give a signal indicating that the calling party has releasedbut that the called party is holding this connector circuit. Releaseofrelay I30 removed groundfrom the 0 lead at contacts I34 to release thepreceding switch train. The connector is retained marked as busy in theselector bank-since the circuit to the resistance battery is open at,contacts I of PI. When the called party then releases, relay IIOreleases and opens the circuit' to relays I80 and I10 at contacts II5.-Relay I10 releases and opens the SUPY. leadto extinguish the alarm.Relay I80 releases, removes ground from the C wiper at contacts I81 torelease the line circuit I00 or I03,- and closes ground'thru contactsI22, I32, I 64, and I92 'to the Strowger switch release magnet I21. Therelease magnet I21 operates to return the Strowger switch to normal. Inthe normal position, the V. O. N. springs release and at contacts I92open the release magnet I21 and at contacts I! close the above tracedground circuit thru contacts ,3 of PI and self-interrupting contacts I91to the sequence switchmagnet I94. The sequence switch automaticallyoperates in a self-interrupting manner to return to its normal position.In the normal position, spring pile-up PI operates to; open theself-interrupting circuit to the sequencelfswitch to-stop the same, andto close resistance battery thru contacts I to the C lead to mark thiscir'cuit'idle I If the called party had released first; release by: cingsubscriber is "the s elector banks.

of the Strowger switch and theasequenc'e switch when the calling partyreleasedwouldtake place in a manner'similar to that previously explainedsk"l ed in the t dates that the-callis for the second hu'ndredsgroup;that t e ringing frequency will be that connected to the Gen. 4 lead andthat the ringing generator battery will be connected to the negativeside of the called line. The sequence switch follows the third series ofimpulses as previously described, in this instance taking nine steps inresponse to the nine impulses, the ninth step taking the switch toposition ll. passed from position I to 8, spring pile-up P5 released andpile-up P6 operated, thus selecting the wiper set standing on the partyline in the second hundreds group of lines. If relay I50 had beenoperated due to a busy condition on the party line in the first hundredsgroup of lines, it will release when spring pile-up P5 releases and willthen re-operate or remain released depending on the condition of theparty line in the second hundreds group of lines. The remaining circuitfunctions are similar to those described previously for completing acall to the party line in the first hundreds group and will not bedescribed.

It should be noted that this invention is not limited to party lineconnectors or the connectors in general but will apply equally well totelephone circuits which are required to function analogously. Numeroususes and adaptations of the invention will occur to those versed in theart and all changes and modifications coming within the scope of theappended claims are embraced thereby.

What is claimed is:

1. In a telephone system, a connector circuit for connecting with partyline bank outlets comprising a primary stepping mechanism responsive toa first series of impulses for causing said connector to step in aprimary direction, a secondary stepping mechanism responsive to a secondseries of impulses for causingsaid connector to step in a secondarydirection, a pulsing circuit for transmitting impulses connected to saidprimary. stepping mechanism, and a plurality of signal sources forproviding the various ringing'signals, a sequence switch mechanism,means for operating said sequence switch once after each said first andsecond series of impulses, first circuit means for disconnecting saidpulsing circuit from said primary stepping mechanism and for connectingsaid pulsing cir-' cuit to said secondary stepping mechanism, meansincluded in said sequence switch mechanism for operating said firstcircuit means on operation of said sequence switch mechanism aftertransmission of said first series of impulses, second circuit means fordisconnecting said pulsing circuit from said secondary steppingmechanism and for connecting said pulsing circuit to said sequenceswitch mechanism, second means included in said sequence switchmechanism for operating said second circuit means on operation of saidsequence switch mechanism after transmission of said second series ofimpulses, and means operated by said sequence switch mechanismresponsive to a third series As the sequence switch ofimpulses-transmitted 'ovei said pulsing circui-t' for selecting o'neof'said-"si'gnal' sources dependent (in the'humber of impulses insaid'th d serie's; 2; In a telephone system as claimed in claim 1';sfets in said connector- 01" cuit a i pair 5 of =wiper rqrconnecti-ngwith a pain or {party 1in outlets iii-espouse to tli' ertical andrarystepping'of the connector; pair l1" operative to select a certain'ohe' of said pair of wiper sets, ,,and means operated by said sequenceswitchmechanism'responsive to said third series of impulses foroperating one or the other of said pair of means dependent on the numberof impulses in said third series.

3. In a telephone system as claimed in claim 1, third circuit means fordisabling said pulsing circuit, and means operated by said sequenceswitch mechanism responsive to said third series of impulses foroperating said third circuit means.

4. In a telephone system, a ZOO-line connector for use with party lineshaving divided ringing comprising a first selecting device, including adriving means a second selecting device in cluding a driving means and apulsing circuit for transmitting impulses, a third selecting deviceincluding a driving means, a first circuit means connecting said pulsingcircuit to said first selecting device driving means, a second circuitmeans for connecting said pulsing circuit to said second selectingdevice driving means, a third circuit means for connecting said pulsingcircuit said second circuit means and operate said third circuit means,a fourth circuit means for selecting one of the two hundreds groups oflines, a fifth circuit means for" selecting a proper ringing signal, a,sixth circuit means for selecting one of the sides of the party line towhich the selected ringing signal is to be connected, and means includedin said third selecting device for operating said fourth, fifth andsixth circuit meansin response to a third series of impulses.

5. In a telephone system, a switch arranged to select among groups ofoutlets in response to a plurality of impulses, a pulsing circuit fortransmitting impulses, a first driving means in said switch connected tosaid pulsing circuit and operated in response to a first series of Iimpulses transmitted thereover to cause said switch to make a firstgroup selection, an impulse responsive device, circuit means associatedwith said pulsing circuit for operating said impulse responsive deviceafter transmission of said first and a second series of impulses, asecond driving means in said switch, means operated under control of sadimpulse responsive device responsive to operation thereof aftertransmission of said first series of impulses for transferring saidpulsing circuit from said first driving device to said second drivingdevice, said second driving device operated in response to a secondseries of impulses transmitted oversaid pulsing circuit to cause saidswitch to make a second group selection, means operated by said impulseresponsive means after transmission of said sec- 0nd series of impulsesfor transferring said REFERENCES CITED 5 pulsing circuit from saidsecond driving device The following references'are of record in the tosaid impulse responsive device, said impulse meet this patent:responsive device operated in response to a third series of impulsestransmitted over' said pulsing 5 P PATENTS circuit to make furtherselections, circuit means Number Name v Date for disabling said pulsingcircuit. and means con- 1,512,584 Dunham Oct. .21, 1924 trolledby saidimpulse'responsive device for 1,604,550 Deakin Oct. 26, 1926 operatingsaid-circiut'means. 1,655,061 Jordan Jan. 3, 1928 10 2,179,826 MayNow-14,1939

LAB N 2,515,733 Lomax July 15,1950

